Risk Factors for Oral Cavity and Oropharyngeal Cancers

A risk factor is anything that changes a person’s chance of getting a disease such as cancer. Different cancers have different risk factors. For example, exposing skin to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for many cancers.

There are different kinds of risk factors. Some, such as your age or race, can’t be changed. Others may be related to personal choices such as smoking, drinking, or diet. Some factors influence risk more than others. But risk factors don't tell us everything. Having a risk factor, or even many, does not mean that a person will get the disease. Not having any risk factors doesn't mean that you won't get it, either.

Some people who have oral cavity or oropharyngeal cancer have few or no known risk factors, and others who have risk factors never develop the disease. Even if someone does have risk factors, it's impossible to know for sure how much they contributed to causing the cancer.

Tobacco and alcohol

Tobacco and alcohol use are 2 of the strongest risk factors for oral cavity and oropharyngeal cancers.

Tobacco use

Most people with oral cavity and oropharyngeal cancers use tobacco, and the risk of developing these cancers is related to how much and how long they smoked or chewed.

Smokers are many times more likely than non-smokers to develop these cancers. Tobacco smoke from cigarettes, cigars, or pipes can cause cancers anywhere in the mouth or throat. It can also cause cancers of the larynx (voice box), lungs, esophagus (swallowing tube), kidneys, bladder, and many other organs.

Pipe smoking is linked to a very high risk for cancer in the part of the lips that touch the pipe stem.

It's important for smokers who have been treated for oral cavity or oropharyngeal cancer to quit smoking, even if their cancer seems to be cured. Continuing to smoke greatly increases their risk of developing a second cancer in the mouth, throat, larynx (voice box), or lung.

Oral tobacco products (snuff, dip, spit, chew, or dissolvable tobacco) are linked with cancers of the cheek, gums, and inner surface of the lips. Using oral tobacco products for a long time is linked to a very high risk. These products also cause gum disease, destruction of the bone sockets around teeth, and tooth loss. It's also important for people who have been treated for oral cavity or oropharyngeal cancer to give up all oral tobacco products.

Drinking alcohol

Drinking alcohol increases the risk of developing oral cavity and oropharyngeal cancers. About 7 out of 10 patients with oral cancer are heavy drinkers.

Drinking and smoking together

The risk of these cancers is even higher in people who both smoke and drink alcohol, with the highest risk in heavy smokers and drinkers. According to some studies, the risk of these cancers in heavy drinkers and smokers may be as much as 100 times higher than the risk in people who don’t smoke or drink.

Betel quid and gutka

In Southeast Asia, South Asia, and certain other areas of the world, many people chew betel quid, which is made up of areca nut (betel nut), spices, lime, and other ingredients. Many people in these areas also chew gutka, a mixture of betel quid and tobacco.
People who chew betel quid or gutka have an increased risk of cancer of the mouth.

Human papillomavirus (HPV) infection

Human papillomavirus (HPV) is a group of more than 150 types of viruses. They're called papillomaviruses because some of them cause a type of growth called a papilloma. Papillomas are not cancers, and are more commonly called warts.

HPV types are given numbers. Infection with certain types of HPV can cause some forms of cancer, including cancers of the penis, cervix, vulva, vagina, anus, mouth, and throat. The type linked to throat cancer (including cancer of the oropharynx) is HPV16.

Most people with HPV infections of the mouth and throat have no symptoms, and only a very small percentage develop oropharyngeal cancer. At this time the US Food and Drug Administration has not approved a test for HPV infection of the mouth and throat.

The number of oropharyngeal cancers linked to HPV has risen dramatically over the past few decades. And research has shown that these cancers are becoming more common in younger people
with no history of alcohol abuse or tobacco use than they were in the past. HPV DNA (a sign of HPV infection) is found in about 2 out of 3 oropharyngeal cancers and in a much smaller fraction of oral cavity cancers. The reason for the rising rate of HPV-linked cancers is unclear, although some think that it could be because of changes in sexual practices in recent decades,
in particular an increase in oral sex.

Gender

Oral and oropharyngeal cancers are twice as
common in men than in women. This might be because men have been more likely to use tobacco and alcohol in the past.

Age

Cancers of the oral cavity and oropharynx usually take many years to develop, so they're not common in young people. Most patients with these cancers are older than 55 when the cancers are first found. But this may change as HPV-linked cancers become more common.

Ultraviolet (UV) light

Sunlight is the main source of UV light for most people. Cancers of the lip are more common in people who have outdoor jobs where they are exposed to sunlight for long periods of time.

Poor nutrition

Several studies have found that a diet low in fruits and vegetables is linked with an increased risk of cancers of the oral cavity and oropharynx.

Weakened immune system

Oral cavity and oropharyngeal cancers are more common in people who have a weak immune system. A weak immune system can be caused by certain diseases present at birth, the acquired immunodeficiency syndrome (AIDS), and certain medicines (such as those given after organ transplants).

Graft-versus-host disease

Graft-versus-host disease (GVHD) is a condition that sometimes occurs after a stem cell transplant. During this medical procedure, blood stem cells from a donor are used to replace bone marrow that has been destroyed by disease, chemotherapy, or radiation. GVHD occurs when the donor stem cells recognize the patient’s cells as foreign and launch an attack against them. GVHD can affect many tissues of the body, including those in the mouth. This increases the risk of oral cancer, which can occur as early as 2 years after GVHD.

Genetic syndromes

Fanconi anemia is a condition that can be caused by inherited defects in several genes that help repair DNA. People with this syndrome often have blood problems at an early age, which may lead to leukemia or aplastic anemia. They also have a very high risk of cancer of the mouth and throat.

Dyskeratosis congenita is a genetic syndrome that can cause aplastic anemia, skin rashes, and abnormal fingernails and toenails. People with this syndrome also have a very high risk of developing cancer of the mouth and throat at a young age.

Lichen planus

This disease occurs mainly in middle-aged people. Most often it affects the skin (usually as an itchy rash), but it sometimes affects the lining of the mouth and throat, appearing as small white lines or spots. A severe case may slightly increase the risk of oral cancer.

Unproven or controversial risk factors

Mouthwash

Some studies have suggested that mouthwash with a high alcohol content might be linked to a higher risk of oral and oropharyngeal cancers. But recent research has questioned these results. Studying this possible link is complicated by the fact that smokers and frequent drinkers (who already have an increased risk of these cancers) are more likely to use mouthwash than people who neither smoke nor drink.

Irritation from dentures

It's been suggested thatlong-term irritationof the lining of the mouth caused by poorly fitting dentures is a risk factor for oral cancer. But many studies have found no increased risk in denture wearers overall.

Poorly fitting dentures can tend to trap agents that have been proven to cause oral cancer, such as alcohol and tobacco particles, so denture wearers should have them checked by a dentist regularly to ensure a good fit. All denture wearers should remove their dentures at night and clean and rinse them thoroughly every day.

Oral health

Studies have suggested the overall health of the mouth, teeth, and gums may impact oral cavity and oropharyngeal cancer risk because of changes in the normal bacteria in the mouth.
Poor oral hygiene, which can lead to tooth loss, may also be linked to these cancers. Overall survival may also be affected.
More research is needed, but regular dental visits, as well as brushing and flossing, may lessen these risks and have many other health benefits, too.

Centers for Disease Control and Prevention. Betel Quid with Tobacco (Gutka). December 1, 2016. Accessed at www.cdc.gov/tobacco/data_statistics/fact_sheets/smokeless/betel_quid/index.htm on February 22, 2018.